Why use EDM? How does the EDM help?
The Entity Framework enables developers to reason about and write queries in terms of the EDM model rather than the logical schema of tables, joins, foreign keys, and so on. Many enterprise systems have multiple applications/databases with varying degrees of normalization, different schema styles depending on the group that developed it, and different naming conventions for tables and columns. Furthermore, in complex systems the entities of interest may be scattered across multiple rows in multiple tables, and changes to the logical schema can be painful to track within applications. By adding an additional level of abstraction, the EDM insulates the developer from the low level details of the logical model, and frees them to focus on the essential aspects of the application/problem at hand. For more information, see Introducing the Entity Framework. Pasted from < http://blogs.msdn.com/adonet/archive/2007/05/30/entitysql.
